This application requests funding for a CompuCyte laser scanning cytometer optimized for quantitative analysis of fluorescence in fixed and living cells and tissues. The laser scanning cytometer will become part of the University of Wisconsin Comprehensive Cancer Center's flow cytometry facility, and will serve the entire University of Wisconsin research community. The facility will serve investigators from multiple departments throughout the University of Wisconsin campus who need the instrument to quantify fluorescence in homogenous and heterogeneous cell populations with both live and fixed samples. The major users will require the CompuCyte laser scanning cytometer to (1) provide quantification of fluorescence in adherent cells and (2) analyze heterogeneous populations of cells within mixed populations or tissues. All major users have experience in fluorescence microscopy and flow cytometry analysis and have determined that the equipment currently available at the University of Wisconsin cannot meet their needs. The laser scanning cytometer will be installed in a flow cytometry facility laboratory located near the laboratory of the PI at a location central to the other investigators. Personnel experienced in flow cytometry will staff the facility and financial support for the facility will be provided by the University of Wisconsin Comprehensive Cancer Center. In summary, the application will serve the needs of a broad NIH-funded scientific community at the University of Wisconsin campus and will provide a significant advance over the current technology available for fluorescence analysis. [unreadable] [unreadable]